Various manufacturing processes expose semiconductor process chamber components to high temperatures, high energy plasma, a mixture of corrosive gases, high stress, and combinations thereof. These extreme conditions may erode and/or corrode the chamber components, increasing the chamber components' susceptibility to defects.
Protective coatings used for reducing defects on chamber components due to harsh processing conditions are typically deposited on chamber components. Protective coatings may be deposited by a variety of techniques, including but not limited to, thermal spray, sputtering, ion assisted deposition (IAD), plasma spray, evaporation techniques, atomic layer deposition, chemical vapor deposition, and so on. Some of these techniques may generate protective coatings with abnormally large crystal grains. Abnormally large crystal grains may increase the protective coating's surface roughness and provide a pathway for diffusion of chemicals through possible cracks between the grains or through grain boundaries.